Chassis flexibility is a critical feature of a chassis of a go-kart used in oval-track racing, a sport commonly enjoyed in the United States. Go-karts having flexible chassis are better able to maintain both rear wheels on the track surface through comers at high speeds compared to go-karts having more inflexible chassis. The retention of both wheels on the track surface is important because racing go-karts have live rear wheel axles.
Chassis for racing go-karts are generally constructed from sections of tubing which are welded together to define a frame. Typically all the tubular sections of the chassis are formed from 1.125 inch tubing and, until the present innovation, this dimension was adopted de facto as an industry standard in oval-track racing. A few manufacturers have formed all of the tubular sections of a chassis from 1.25 inch tubing, but such a chassis has been found to exhibit a high degree of inflexibility, i.e., lack of roll in cornering, and consequently a driver of a go-kart having a chassis formed from 1.25 inch tubing has found himself at a disadvantage to his competitors. Racing go-karts built with the 1.125 inch tubular chassis have thus exhibited a competitive edge and therefore enjoyed unsurpassed commercial success in the oval-track racing industry over the few racing go-karts built with the 1.25 inch tubular chassis.
In Europe, go-kart race tracks generally include hairpin turns and are not oval, and when racing on these tracks it is more advantageous to use an inflexible chassis with minimized roll in cornering. Go-karts used in European style racing therefore are typically formed from 32 millimeter tubular sections (approx. 1.26 inch tubing), and go-karts utilizing the 1.125 inch tubular sections exhibit substandard racing performance. A modification to this conventional European style chassis includes using front and middle transversely extending tubular members formed from 35 millimeter tubing which tends to reduce the flexibility of the chassis even more in cornering.
Various types of chassis for different types of go-karts are well-known and disclosed, for example, by the following U.S. Pat. Nos.: 4,799,708; 4,732,819; 4,682,668; 4,629,023; 3,829,117; 3,799,283; 3,557,894; 3,115,350; 3,022,846; 2,919,981; and 2,919,139.
A particular go-kart chassis that has enjoyed wide acceptance in the oval-track racing industry is disclosed by Amundsen et al., U.S. Pat. No. 5,265,690, which is incorporated herein by reference. The chassis shown in FIG. 1 thereof is formed from 1.125 inch tubing, see Amundsen et al., col. 1, lines 31-32, and includes two tubular side members (12,14) which longitudinally extend the length of the go-kart chassis with front, middle, and rear tubular transversely extending members (16,18,20) extending therebetween. A flat bar (21) is also secured between the side members (12,14) for supporting a floor board, and a further tubular member (24) extends parallel to part of the side member (12) towards the rear of the chassis for supporting a motor. Furthermore, the motor supporting member (24) is welded to the rear transversely extending member (20) and to the side member (12), and the front and rear transversely extending members (16,20) are welded to the side members (12,14). The middle transversely extending member is welded to the side member (14) and to the motor supporting member (24).
Another oval-track racing chassis that has enjoyed much success in the oval-track racing industry is disclosed in FIG. 1 herein and has also been completely formed from 1.125 inch tubing. In particular, two tubular side members 102,104 longitudinally extend the length of the go-kart chassis and front, middle, and rear tubular transversely extending members 106,108,110 extend therebetween. A motor supporting tubular member 112 extends parallel to part of side member 102 towards the rear of the chassis and also includes at one end a perpendicular section 114 formed integral therewith which is secured to the side member 102. The motor supporting member 112 is secured at its opposite end to an intermediate tubular member 116 which extends between and is welded to the side member 102 and the middle transverse member 108. The middle and front transversely extending members 108,106 are welded to the two side members 102,104, and the rear transverse member 110 is welded to the side member 104 and the motor supporting member 112.
While improvements have been made over the years to go-karts as disclosed in the above-identified patents, for example, further refinements and innovations leading to an additional competitive edge is always needed to insure successful oval-track racing. The present invention is designed to provide such a desired and necessary competitive edge.